2023 Hyundai Sonata Powertrain (other) Problems

I own a 2023 Hyundai Sonata SEL. Over approximately three years, the vehicle experienced four separate incidents involving sudden loss of engine power and recurring fuel injector/powertrain problems. Three of these incidents occurred while the vehicle was being driven on interstate highways, creating serious safety concerns. The first incident occurred on XXX, on [XXX] [XXX]. My daughter was driving the vehicle at the time when it suddenly lost power while traveling on the interstate. She had to maneuver the vehicle to the shoulder under unsafe traffic conditions. The second incident occurred on XXX, on [XXX] near [XXX]. I was driving the vehicle when it again experienced sudden loss of power while traveling at highway speed. The third incident occurred on XXX, in [XXX]. The vehicle experienced another significant power-loss event and required roadside assistance. The fourth incident occurred on XXX, on [XXX]. The vehicle again experienced a sudden loss of engine power while I was driving on the highway. Despite multiple repair attempts, including repairs related to the fuel injectors, the same or substantially similar power-loss problem continued to recur. Because the vehicle has repeatedly lost engine power while being driven, including multiple incidents at interstate highway speeds, I believe this recurring condition presents a serious safety risk. I am reporting these incidents so NHTSA can evaluate whether this may represent a broader safety-related defect affecting this vehicle model. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11755422

Incident

Jun 30, 2026

The contact owns a 2023 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the transmission shifted into neutral(N) and failed to shift into park or drive on three occasions. The vehicle was restarted. After restarting the vehicle, the vehicle was shifted into drive, and the contact continued driving. The message that the vehicle could not be shifted into other gears was displayed. The vehicle was originally purchased in another state. The vehicle was taken to the local dealer to be diagnosed. The dealer determined that the battery and fuel injector pump needed to be replaced. The vehicle was repaired; however, the failure recurred. The manufacturer was not contacted regarding the failure. The failure mileage was approximately 50.

NHTSA ID

11744098

Incident

Jun 13, 2026

Mileage

50 mi

This is an extremely common issue plaguing Hyundai & Kia vehicles with the Theta III 2.5L Turbo engine, Such as Kia K5 GT, Hyundai Sante Fe, Hyundai Santa Cruz, & Hyundai Sonata N-Line. Its a failing ITM (integrated thermal management) unit or otherwise known as an ITMS unit. There is a rod within the ITM that prevents proper control of the flow of cooling the oil and engine coolant of the engine. Results in Cooling issues, such as a cold lower radiator hose while the engine is hot, or 'limp mode' during acceleration, that causes a sudden loss of power while trying to merge on the expressway. There has been other Kia models and years that have had TSB's related to fixing this issue, but Hyundai has released nothing. I have uploaded an example of one of the TSB's that do not apply to my car. Technical symptoms often include: Fans running 100% full duty (high) while the lower radiator hose stays cool. Or Fuel dilution or a 'rich' running engine. Because the engine is overcooling that keeps the car's fueling rich and in a open loop mode affecting emissions and contaminating oil. Personal Details of exactly what happened when i noticed mine was failing. I ran home on my lunch break, and while accelerating on a ramp to get up on a highway, my car started beeping and flashing "Engine Overheated" and i immediately let off the gas with preparation to pull over. The second i left off the gas, the coolant temp within 1-2 seconds went from a little over 3/4 the way up the gauge back to normal a little below half temp. I resumed driving a 3 mile drive back to work, with it showing normal temps the rest of the way. I popped the hood when i got to work to see if coolant was low, and it was completely normal, a little over halfway between the min/max lines. The car continues to run hot, often with the cooling fans running at 100%.

NHTSA ID

11737860

Incident

Feb 25, 2026

Vehicle WITHOUT WARNING will start to jerk then go into “limp” mode. Pressing on gas pedal makes the revving noise but with not physical movement made. This has happened on MULTIPLE occasions (13 times in 4 months) including in the snow and on the interstate while driving at 70mph where no shoulder is available to pull over. Car was taken to dealership 3 different times with no actual diagnosis, tests were ran all 3 times with nothing. Eventually the 3rd time at the dealership I was told the transmission was being replaced although they were not sure what actually caused the issue (this is written in the service report by the rep/mechanic). CAR REMAINS UNSAFE AND UNRELIABLE. Livelihood of myself, family and other drivers is at risk EVERYTIME I put the car in drive due to this mechanical issue. NO WARNINGS NO POWER NO FIX.

NHTSA ID

11721841

Incident

Dec 22, 2025

Car was parked, full stop, doors shut, seatbelt on. Foot on brake. Car then seemed to lurch forward by itself forward hitting parking cement block. Put in reverse to back away and car stayed still...then I tapped the gas again to back up and insted vehicle plowed forward.instead.of reverse ...went over the parking block and hit concrete beam in front, when the car should have backed up in reverse. I'm a person who drives speeed limits, and ulta careful when i drive, and parked at this place/spot for years. This has never happened not sure why it did. No injuries or other people involved thank god, but scared the heck out of me. Wracking my brain, my recalls and software and service appts are up ro date.Nothing out of ordinary that day. I'm confused and shaken, why the first lurch forward and why did going in reverse move it forward? ugh. It drove home fine. Commute to work daily for years, no issues. All I can guess is gear didn't click to reverse and was somehow in drive? Ive been going over the possibilities in my head for human error but they dont make sense - again I've been driving for 40 years. If it happens to other models, would love to know! Car will go to repair tomorrow as "my fault" via insurance, hoping they can see more if any error codes, to at least say if Reverse didn't engage or something else happened. May have been human error but it's so out of the ordinary for me. Thanks!

NHTSA ID

11718993

Incident

Feb 18, 2026

At least 8 times when driving the car the transmission switches from the drive “d” position to the park “p” position and I have to cut off the car and then restart. It is very dangerous as I can be rear ended which can result in personal injury as well as an insurance claim. I’ll put the last date it occurred but started experiencing soon after I bought car.

NHTSA ID

11716374

Incident

Jan 21, 2026

On January 6, 2026, during my morning commute in heavy traffic, my 2023 Hyundai Sonata engine unexpectedly turned off, causing a sudden loss of power. This created an extremely dangerous situation, and I came very close to being involved in a major collision. While I was fortunate to avoid a crash, the incident posed a direct threat to my safety and life because of the dense surrounding traffic.

NHTSA ID

11709400

Incident

Jan 6, 2026

2023 Sonata N-Line, complete loss of power while driving on seven (7) occasions over the past year. In all cases above 60mph creating a dangerous condition to myself and fellow drivers while attempting to pull to the side of the road while rapidly losing speed. In all seven (7) cases, the DTC code is P065312. I have asked the dealership to note the recurring issue in my service records and I have reached out to Hyundai, mostly so that if I am involved in a serious accident because of this issue, there is a paper trail for legal purposes. The dealership folks are nice but basically unless the car rolls into the dealership with smoke pouring out of the engine, they want to charge a diagnostics fee and keep the car for multiple days which isn't helpful because like most, I need the car and the issue is extremely sporadic. It is disappointing and I hope Hyundai takes note and provides remedy for the issue sooner rather than later as this is my sixth (6th) Hyundai vehicle and really do like the car otherwise. All incidents below: 01/23/2025 - 9531 miles 01/20/205 - 9128 miles 12/15/2024 - 5500 miles 12/13/2024 - 5374 miles 11/22/2024 - 2409 miles 01/12/2024 - 568 miles 01/08/2024 - 554 miles

NHTSA ID

11638560

Incident

Jan 23, 2025

For like the fifth time while I'm driving the car just dies. I can be going 55 I can be going 70 and the dashboard lights up like a Christmas tree and the car just dies. I have to pull the car over to the side and I have to turn it off and restart it again. And then about 3 days later the check engine light will go away. This seems like a software issue but Hyundai and my local dealer cannot help me I'm going to get killed in this thing. I can't take it on the highway I can barely take it down the street because it could go out on me while I'm driving and I could be in the middle lane and I could get killed. They tell me they can't replicate the issue but it's a software issue somebody needs to do something before I get killed. Every single light on the dashboard turns on and the engine just dies. This is like the fifth time this has happened. I think this car is a lemon but no one will help me.

NHTSA ID

11622068

Incident

Oct 26, 2024

On 4 occasions in the last 4 months when I push the gas my cars rpm will go up but the car does not accelerate. This has happened twice on the interstate when trying to merge with trsffic and twice in city traffic, once when making a lefthand turn across oncoming traffic and once just driving down the road. I have taken the car to 2 separate dealerships for a total of 3 times and they drive it a few miles and tell me they can't duplicate the issue. I just picked my car up today after leaving it for 6 days. On my way home the emergency breaking system activated for no reason slowing my car down on the interstate. Both of these issues could get me or someone elas killed. I have not even had this car for 2 years and I am afraid to drive it. Please help. I know I am not the only person with this issue because I can see others on the internet who also have been told that the dealership can't dupe the problem. Even the dealership I just picked it up from said they had another car there with the same problem that they can't duplicate so there is nothing they can do.

NHTSA ID

11619305

Incident

Jun 10, 2024

I have been having transmission issues the whole time I've had the car. There is a delay upon take off, and it bogs down instead of downshifting. I was driving my son to school and made a left turn. It started to go but then delayed for 10 seconds before suddenly taking off. If the on coming traffic had been closer, they would've hit us. The dealer has reproduced the problem but can't get enough information for the tech line to approve a new transmission even though the dealership has repeatedly said that is what it needs. I've never had a warning light on it. it's been in the shop for it this time since 7/26/24.

NHTSA ID

11615169

Incident

Sep 2, 2024

Hello, I have Hyundai Sonata 2023. The fuel tank of this car is expanded on [XXX]. I have never heard about this issue to any cars. I took my car to dealership they said they don’t know why this happened and they said they cannot fix it, my car at the dealership more than a month. I have created a case with Hyundai corporate office in CA, it’s been a month since this case was created and I could reach out to my case manager only twice for this period of time. They are keep saying they are working on it, but no results they don’t even look at my car. Today I barely could reach my case manager and she told me that this is not under warranty and I will need to fix it out of my pocket. When I bring the car to the dealership they told me this not under warranty since warranty was up to 60k miles, I have 90k I asked them to fix it and I will pay but they said they don’t know how to fix it. Today I have researched and found that this issue is really common among Kia K5 and Hyundai Sonata’s 2021 2024, I will provide a link here: [XXX] Please check this link and you can see that most of the cars fuel tanks are expanded and back seats popped up. I have same exact problem. Kia asked drivers to inspect the cars with this issue and they said they will fix it for free since this is fuel tank defect. But what should I do with my Hyundai Sonata. I have same exact issue as you see at the link I have provided. I had powertrain DTC PO451 since march of this year dealership said just check if gas cap is on properly, but this caused this issue I see Hyundai will not help me it will almost 2 month I don’t have my car and I am still paying for it, please let me know what I can do Thank you! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11611733

Incident

Jul 9, 2024

I was driving on the interstate at interstate speeds and the car started to lose power. I was able to steer the car to a safe location and call roadside assistance. It appears that the engine control system had a failure in one of the control modules. The problem was reproduced at the time that I dropped the car off with the service center. The history of the issues for the vehicle are available. My safety was put at risk because the car lost power at high speed and I was only able to limp to a safe location. No warning lights happened until the issue was already taking place. After being notified by my Hyundai app, I was able to discover that the vehicle had a history of having this code (I have only owned the car for 32 days)

NHTSA ID

11603350

Incident

Jul 19, 2024

The car would not accelerate, nor switch gear while I'm driving middle of the highway. The car engine started to shake after my car wouldn't switch gear. The car engine would not start after turning the car off and caused a engine misfire. The transmission gear has a hard time switching gear from 0-40mph. This same incident occurred twice since purchasing the car in late November 2022.

NHTSA ID

11586734

Incident

Apr 18, 2024

Transmission goes into limp mode Please note this is an N line and shift points are low taking off from a light vehicle goes into limp mode in first 150' cars to the rear almost ran into the back of the vehicle. Car is 2 days old and I have an appointment tomorrow to have it looked at. This sounds like similar problem that caused a recall last year on the 2022. This is a dual clutch auto.

NHTSA ID

11546820

Incident

Sep 22, 2023

I was driving on the freeway, at the speed limit, cruising along. Then all of a sudden, my vehicle starts to decelerate from 65 MPH and I push the gas, thinking I must have let up too much on the pedal. However, that only causes the RPM to drastically rise with NO change in my speed. I thankfully managed to maneuver from the far left lane to the freeway shoulder on the far right. The whole time, my speed was around 40 MPH and dropping drastically. Trying to safely navigate a slowing vehicle on a 65+ Texas freeway is an adrenaline-rush that I wouldn’t wish on anybody. I was severely panicking. I was almost hit by several vehicles in my maneuvering. I could have died last night. Once on the shoulder, I tried to start my car. I thought it may be a battery issue, but it turned on. It didn't start, though. The lights came on, as did all of the typical system/dash lights that usually indicate when a car’s engine hasn’t “turned over.” I used Bluelink to call for roadside assistance (since I’m only a little over 2 months into ownership) and waited. I was escorted off of the freeway to safety — thanks to a 3-car police escort AND free city tow trucks — and eventually picked up by Hyundai-serviced AAA. The latter then towed my vehicle to the dealership where I bought my Sonata. My car is currently being checked/inspected by my dealer (North Freeway Hyundai) and I only have gotten the following notice from Bluelink: "A possible condition with your Engine Control System has been detected with your 2023 SONATA on 02/22/2023 at 07:23 am CST. A full system check is recommended to be done soon." I checked and there are no open recalls (currently). Even more concerning, my car recently underwent complimentary maintenance, including an oil change, through my dealer (on February 13, 2023 - I have the receipt), was good on gas, and had no warning lights displaying. Until it stopped running — the time I tried to start it on the side of the road, the dash showed an “engine” light.

NHTSA ID

11508589

Incident

Feb 21, 2023